Question: Is the sieve you use similar to one you'd use in a kitchen? I'd guess it is a lot bigger...?

Rowena Fletcher-Wood answered on 9 Mar 2014:

My sieves are probably more like sponges – 3-dimensional with complicated pore structures running through them that love to take up water. However, unlike sponges they can’t be squeezed: they are rigid like sieves.

Being molecular sieves they are made up of (mostly) silicon and aluminium atoms joined by four points via oxygens. This is like a large group of people joining hands and feet with each other. They can extend a long way in space, but the bits making them up are tiny.

In the lab, they often look like white powders. If you rub them between your fingers they feel grainy: this is because they are actually crystals full of holes. The crystals are about 4 micro-metres x 4 micro metres x 4 micro metres each. I can see them through an imagining microscope called a scanning electron microscope. I have added a picture to the “work pictures” on my profile to show you.